Hey,
Bachelor of Science in Nursing or B.Sc Nursing is a four-year undergraduate course.B.Sc Nursing is based on entrance exams held between April-June.
Different universities conduct their respective entrance tests like Goa Common Entrance Test,AISECT University Entrance Examination,Aliah University Admission Test,SAAT 2019,IGNOU OPENNET 2019,AJEE 2019 and many more.
The entrance test  of AJEE is on 30 June 2019,ITM NEST 2019 and the entrance test is 26 July.
Hope this helps.
Good luck.